Crystal detector for wireless telegraphy



Patented Mar. 28, 1922.

FNI v A BONNEFONT CRYSTAL DETECTOR FOR WIRELESS TELEGRAPHY.

APPLICATION run) NOV. 9. 1920.

ANTOINE BONNEFONT, OF PARIS, FRANCE.

CRYSTAL DETECTOR FOR WIRELESS TFLEGRAPHY.

Specification of Letters Patent.

llatentcd Mar. 28, 1922.

Application filed November 9, 1920. Serial No. 422,804.

. To all whom it may concern:

Be it known that I, AN'roINn Bonner-our, a citizen of the Republic ofFrance, residing at 71 Rne Vandamme, Paris, Seine, France, have inventedcertain new and useful improvements in Crystal Detectors for WirelessTelegraphy ;and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same,reference being had to the'accompanying drawings, and to letters orfigures of reference marked thereon, which form a part of thisspecification.

Crystal detectors are used in wireless to legraphy in which the mostcommonly employed device for locating the sensitive points comprises apivoted arm ending in a coiled spring which terminates in a point. Thisarm is operated by hand, and the entire device is necessarily open andexposed to dust, whence will follow the rapid dc terioration of thecrystals. ()n the other hand, the pressure of the spring is notadjustable, although this -feature is specially desirable for adjustingthe points to the greatest sensitiveness.

This invention comprises a mechanical device for locating the sensitivepoints whereby the crystal and the exploring point maybe enclosed whileat the same time permitting the proper exploration of the crystal to becarried out as well as the ad justment of the point in order to obtainthe best ell'ect of sound. These adjustments are effected by rotating asuitable head which is operated from the outside.

The accompanying drawing which is given by way of example shows anembodiment of this invention.

ig. l is a section of the complete device.

Fig. 2 is a modified form of: the exploring mechanism.

The device comprises a base 8 in insulating material of any suitablekind having disposed thereon a suitable metal cap 0 containing thedetector substance p; said cap is rotatable by hand by rather hardfriction in a metal sleeve (1 secured to said base by a metal screw 1)which serves at the samc time to secure in place the current contactplate Z; upon said base is also mounted a shaft 1!. having slidablethereon a flanged sleeve c carrying anexploring spring r coding in apoint which comes near said shaft c, this being carried out to preventthe coils of the spring from vibrating under slight shocks.

A spring '2 presses said. flanged sleeve towards the cap 0. A metalsocket a! has dis;- posed therein said shaft a and a screw e secures inlace the second current contact plate Z '1 he exploring device isoperated by a rod :5 provided with a stud b milled at the end thereofand disposed in eccentric position with reference to the rod t; said rodcarries at the outer part an operating head 6 a spring r maintains therod 13 in the lower position a1u],'provides a suitable hral ing actionfor the maneuvering oi the device. The device is operated in thefollowing manner. Upon rotating the outer head, the eccentric stud 7)describes a circumtereime about the axis X-X, and the flanged sleeve cwhich is held pressed against the milled part of the stud will followall the movements ofthe latter.

1. The stud eil'ects a reciprocating move ment from the endpositionshown in the drawing to the opposite position which c0- incidcsapproximately with the axis X-X.

Vi'ith this reciprocating movement is combined a second movementconsisting in a rotary motion about the axis Y-Y produced by theactuating cit'cct oi the eccentric milled stud which acts as a frictionroller. This movementis variable, being null when the flange coincideswith the axis X-X and a maximum when in the position shown in thedrawing.

The exploring member r is thus caused according to these various motionsto move forward or lmckward, and then at substantially the end'o'l eachbackward stroke it rotates in order to return to its position in contact with the crystal but at another point on the latter and at thismoment without rotation. It will thus be observed that in order toadjust the-pressure at any point, it will sutlice to rotate theregulating head in either direction.

When rotating about the shaft (1., the are ploring point makes contactwith the crystal at the points located on u circumference having Y'Y. asa center. To explore other points on the crystal it will sullice torotate the cap 1: by hand, inasmuch as it is the coccntric position withreference to the axis 'Y Y.

A modified form of the device is shown in Fig. 2, and it comprises twomilled rollers I) and If concentric or not. Against these Ill) tworollers bear the flanged portions 0 and a spaced apart by an elasticmetal washer e thei'langed portion carries a sleeve 0 provided with aneccentric aperture, The exploring member 1 is mounted on the flangedsleeve 6; the spring 1" presses the entire device against the milledrollers. Vi hen oper ated, said sleeves lnove forwardrand back- Wardtogether, but the device produces a relative movement of rotation of oneof said members with reference to the other by reason of the actuatingmovement of the milled rollers 11 and Z) which have different diameters.

Having thus described the nature of my said invention and the best meansI know of carrying the same into practical etiect, What I claim is- 1. Acrystal detector for wireless telegraphy, comprising an insulating base,a crystal disposed within said base and out of contact with the exterioratmosphere, a supporting member for said crystal rotatable about theaxis thereof, a contact point disposed opposite said crystal in theinterior of said base, a spiral spring, a sliding sleeve constituting asupport for the'spiral spring whose end constitutes the exploring point,a rod along which said sliding sle ve is adapt-- ed to slide, saitf rodbeing secured to said base, a spiral spring, a sliding sleeve constituting asupport for the spiral spring whoes end constitutes theexploring point, a rod along which said sliding sleeve is adapted. toslide, said rod being, secured to said base and eccentric-ally disposedwith reference to the axis of the crystal, an exterior actuating head, ashaft in the latter; an eccentric roller mounted on the shaft, and adish secured to said slidingsleeve and contacting with said eccentricroller, the combination represented by saideccentric roller and saidplate being caused to operate at certain times as a friction actuatingdevice.

In testimony that I claim the foregoing as my invention I have signed myname.

ANTUlNE BUNN .EFON

